Interconnection structure having a via structure and fabrication thereof

Abstract

A method of forming an interconnection structure is disclosed, including providing a substrate having a first side and a second side opposite to the first side, forming a via hole through the substrate, wherein the via hole has a first opening in the first side and a second opening in the second side, forming a first pad covering the first opening, and forming a via structure in the via hole subsequent to forming the first pad, wherein the via structure includes a conductive material and is adjoined to the first pad.

What is claimed is: 
     
       1. A method of forming an interconnection structure comprising:
 providing a substrate having a first side and a second side opposite to the first side; 
 forming at least one electric device on the substrate, wherein the at least one electric device comprises a plurality of metal electrodes; 
 forming a via hole through one of the plurality of the metal electrodes of the electric device and the substrate, wherein the via hole has a first opening neighboring the first side and a second opening neighboring the second side; 
 forming a first pad covering the first opening and directly on the at least one electric device, wherein a portion of the at least one electric device is between the first pad and the substrate; and 
 forming a via structure in the via hole subsequent to forming the first pad, wherein the via structure comprises a conductive material and is adjoined to the first pad, and the via structure exceeds the second opening. 
 
     
     
       2. The method of forming an interconnection structure as claimed in  claim 1 , further comprising:
 forming a photosensitive layer on the substrate covering the at least one electric device prior to forming the via hole. 
 
     
     
       3. The method of forming an interconnection structure as claimed in  claim 1 , further comprising forming an insulating layer surrounding a sidewall of the via hole prior to forming the via structure. 
     
     
       4. The method of forming an interconnection structure as claimed in  claim 1 , wherein forming the first pad comprises performing a first metal screen printing process to form the first pad covering the first opening. 
     
     
       5. The method of forming an interconnection structure as claimed in  claim 1 , further comprising forming a second pad covering the via hole subsequent to forming the via structure. 
     
     
       6. The method of forming an interconnection structure as claimed in  claim 1 , wherein forming the via hole through the substrate comprises drilling the via hole through the substrate with a laser beam. 
     
     
       7. The method of forming an interconnection structure as claimed in  claim 1 , wherein forming the via structure is performed by electric plating using the first pad as a seed layer. 
     
     
       8. The method for forming an interconnection structure as claimed in  claim 1 , wherein the metal electrode of the electric device being through by the via hole is a drain electrode. 
     
     
       9. A method for forming an interconnection structure, comprising:
 providing a substrate having a first side a second side opposite to the first side; 
 forming at least one electric device on the substrate, wherein the at least one electric device comprises a plurality of metal electrodes; 
 forming a via hole through one of the plurality of the metal electrodes of the electric device and the substrate, wherein the via hole has a first opening neighboring the first side and a second opening neighboring the second side; and 
 performing a screen printing process on the first side to fill a conductive material into the via hole so as to form a via structure in the via hole and a first pad disposed on the first side and directly on the at least one electric device, adjoined to the via structure, and the via structure exceeds the second opening, wherein a portion of the at least one electric device is between the first pad and the substrate. 
 
     
     
       10. The method for forming an interconnection structure as claimed in  claim 9 , further comprising:
 forming a photosensitive layer on the substrate covering the at least one electric device prior to forming the via hole. 
 
     
     
       11. The method for forming an interconnection structure as claimed in  claim 9 , further comprising forming an insulating layer surrounding a sidewall of the via hole prior to forming the via structure. 
     
     
       12. The method for forming an interconnection structure as claimed in  claim 9 , wherein the metal electrode of the electric device being through by the via hole is a drain electrode.